Sirius Redux

I initially posted most of this on a friend's blog a while back and I wanted to place it here on mine, albeit with a few updates.

Looking up into the heavens has been a part of my nightly routine for as long as I can remember. In the autumn night's sky, you'll be able to see the immense constellation, Orion the Hunter, rise up in the east and see it progress across the sky until morning. I have fond memories of seeing Orion's superstars from October through March, wherever I'd happen to be; either on the backroads of my hometown, or even seeing them out my bus window on my way to Sevilla, Spain. One of the legends surrounding this constellation has it that Orion the Hunter found himself in a battle with Scorpius the Scorpion in ancient times. During this battle, Scorpius fatally wounded Orion, and henceforth, one never sees both constellations at the same time in the night sky; Scorpius predominantly during the spring and summer, and conversely, Orion only during the fall and winter.

Orion is home to many wonderous stellar entities, including the Horsehead Nebula, and the Orion Nebula, which is a cosmic nursery of sorts. The Hubble Space Telescope has explored the region in and around nebula has found what could be future planetary systems. I go way-back with my astronomy knowledge. For instance, my first science fair project, in the second grade, was about stars and constellations. I remember Sirius, Procyon, Cetus, and Antares to name a few. But it was Orion's Rigel that has kept my attention through the years.

Rigel is a supergiant white, type B8 sequence star, that makes one of Orion's knees. It is one of the most luminous objects in the sky, ranking behind the Moon, Venus, Sirius and a few other notable stars, with a +0.12 visual magnitude; Sirius' magnitude is a -1.46. But what makes Rigel, perhaps more notable, is its tremendous luminosity. Sirius, the brightest star in the night sky is only a mere 8.6 lights away. While Rigel on the other hand is a whopping 750 light years away. (A light year is the distance light travels in a year, approximately 5.88 million million million miles. For those of you who can remember, the speed of light is 186,000 km per second.)

If Rigel was as close as Sirius, it's magnitude would be -10 or about the same as one-fifth the Moon's brilliance. Not only that, you would be able to see Rigel during the daytime (!), read by its light on a moonless night(!!), and the night sky would have a bluish-lavender hue to it instead of the pitch black we all know(!!!).

Who knew that shimmering, varied hued star in my new, yet very meager telescope, that frigid Christmas night 22 years ago would hold such importance throughout my life? I'm just glad that I was able to keep pace with Rigel through the years.